IVGCVSW-8275 GpuFsa Op: Add Activation functions available

* Currently Sigmoid and TanH Functions are implemented.

Signed-off-by: Teresa Charlin <teresa.charlinreyes@arm.com>
Change-Id: If9483be9201dfe47b86acc41ec7932725ac2e39e
diff --git a/src/backends/gpuFsa/layers/GpuFsaActivation.cpp b/src/backends/gpuFsa/layers/GpuFsaActivation.cpp
new file mode 100644
index 0000000..4b0773f
--- /dev/null
+++ b/src/backends/gpuFsa/layers/GpuFsaActivation.cpp
@@ -0,0 +1,126 @@
+//
+// Copyright © 2024 Arm Ltd and Contributors. All rights reserved.
+// SPDX-License-Identifier: MIT
+//
+
+#include "GpuFsaActivation.hpp"
+
+#include <aclCommon/ArmComputeTensorUtils.hpp>
+
+#include <arm_compute/dynamic_fusion/sketch/gpu/GpuWorkloadContext.h>
+#include <arm_compute/dynamic_fusion/sketch/gpu/GpuWorkloadSketch.h>
+#include <arm_compute/dynamic_fusion/sketch/gpu/operators/GpuTanh.h>
+#include <arm_compute/dynamic_fusion/sketch/gpu/operators/GpuSigmoid.h>
+#include <arm_compute/dynamic_fusion/sketch/gpu/operators/GpuOutput.h>
+
+using namespace arm_compute::experimental::dynamic_fusion;
+using namespace armnn::armcomputetensorutils;
+
+namespace armnn
+{
+
+arm_compute::Status GpuFsaActivationValidate(const TensorInfo& input,
+                                             const ActivationDescriptor& descriptor)
+{
+    // Create a new workload sketch, for validation purposes
+    auto compileCtx         = arm_compute::CLKernelLibrary::get().get_compile_context();
+    auto workloadContext    = GpuWorkloadContext(&compileCtx);
+    GpuWorkloadSketch sketch{ &workloadContext };
+
+    arm_compute::TensorInfo aclInputInfo = BuildArmComputeTensorInfo(input, input.GetNumDimensions());
+    aclInputInfo.set_are_values_constant(input.IsConstant());
+
+    arm_compute::ITensorInfo* inputInfo = workloadContext.create_tensor_info(aclInputInfo);
+
+    switch (descriptor.m_Function)
+    {
+        case ActivationFunction::TanH:
+        {
+            if ( descriptor.m_A != 1 || descriptor.m_B != 1)
+            {
+                 return arm_compute::Status(arm_compute::ErrorCode::RUNTIME_ERROR,
+                                            "Activation function TanH only works with a=1 and b=1");
+            }
+            return GpuTanh::validate_op(sketch, inputInfo);
+        }
+        case ActivationFunction::Sigmoid:
+        {
+            return GpuSigmoid::validate_op(sketch, inputInfo);
+        }
+        default:
+            return arm_compute::Status(arm_compute::ErrorCode::RUNTIME_ERROR,
+                                       std::string("Activation function currently not supported in GpuFsa: ")
+                                           + GetActivationFunctionAsCString(descriptor.m_Function));
+    }
+
+}
+
+void GpuFsaActivationCreateOp(GpuFsaPreCompiledBlob* blob,
+                              const TensorInfo& input,
+                              const ActivationDescriptor& descriptor)
+{
+    GpuWorkloadSketch* sketch           = blob->sketch.get();
+    GpuWorkloadContext* workloadContext = blob->workloadContext.get();
+    std::vector<arm_compute::ITensorInfo*> inputTensorInfos  = {};
+    std::vector<arm_compute::ITensorInfo*> outputTensorInfos = {};
+
+    arm_compute::TensorInfo aclInput0Info = BuildArmComputeTensorInfo(input, input.GetNumDimensions());
+
+    aclInput0Info.set_are_values_constant(input.IsConstant());
+
+    inputTensorInfos.emplace_back(workloadContext->create_tensor_info(aclInput0Info));
+
+    // Validate operator, check status and update reasonIfUnsupported
+    arm_compute::Status aclStatus{};
+    switch (descriptor.m_Function)
+    {
+        case ActivationFunction::TanH:
+        {
+            aclStatus = GpuTanh::validate_op(*sketch, inputTensorInfos[0]);
+            break;
+        }
+        case ActivationFunction::Sigmoid:
+        {
+            aclStatus = GpuSigmoid::validate_op(*sketch, inputTensorInfos[0]);
+            break;
+        }
+        default:
+            throw InvalidArgumentException(std::string("Activation function currently not supported in GpuFsa: ")
+                                           + GetActivationFunctionAsCString(descriptor.m_Function));
+
+    }
+    const bool supported = aclStatus.error_code() == arm_compute::ErrorCode::OK;
+    if (!supported)
+    {
+        throw BackendCapabilityException("\"GpuFsa\" backend failed during Activation layer validation");
+    }
+
+    arm_compute::ITensorInfo* activationOutputInfo{};
+    switch (descriptor.m_Function)
+    {
+        case ActivationFunction::TanH:
+        {
+            activationOutputInfo = GpuTanh::create_op(*sketch, inputTensorInfos[0]);
+            break;
+        }
+        case ActivationFunction::Sigmoid:
+        {
+            activationOutputInfo = GpuSigmoid::create_op(*sketch, inputTensorInfos[0]);
+            break;
+        }
+        default:
+            throw InvalidArgumentException(std::string("Activation function currently not supported in GpuFsa: ")
+                                           + GetActivationFunctionAsCString(descriptor.m_Function));
+
+    }
+
+    // Temporary fix until fusing attempt is make for GpuFsa backend and Output layer workload is created.
+    outputTensorInfos.emplace_back(workloadContext->create_tensor_info());
+    GpuOutput::create_op(*sketch, activationOutputInfo, outputTensorInfos[0]);
+
+    // Store the TensorInfos within the blob as unique_ptrs to be used later
+    blob->inputTensorInfos  = std::make_unique<std::vector<arm_compute::ITensorInfo*>>(inputTensorInfos);
+    blob->outputTensorInfos = std::make_unique<std::vector<arm_compute::ITensorInfo*>>(outputTensorInfos);
+}
+
+} // namespace armnn
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